3-(2-Bromoethyltosylamino)quinoline 1-oxide (4) reacted with TsCl-NH4OH and TsCl-K2CO3 to afford the 2-aminoquinoline (5) and the 2-quinolinone (8). Cyclization of 5 and 8 under basic conditions gave the piperazino-quinoline (6) and the morpholino-quinoline (9). Similar reactions of 3-(2-bromoethoxy)quinoline 1-oxide (13) in the presence of TsCl gave also the 2-aminoquinoline (14) and the 2-hydroxyquinoline (16), but accompanied with fair amounts of by-products (15 and, 15 and 17). Cyclization of 14 and 16 gave the morpholino-quinoline (18) and the 1,4-dioxano-quinoline (19) in somewhat lower yields.
Synthesis of 2,3-Fused Quinolines from 3-Substituted Quinoline 1-Oxides. Part III. Intramolecular Cyclization of Quinoline 1-Oxides Bearing Active Methylene Groups at the 3-Position in the Presence of Acetic Anhydride
3-N-Alkylcyanoacetamidoquinoline 1-oxides (3a and 3c) react with Ac2O at room temperature in chloroform to afford 1-alkyl-3-cyano-4H-pyrrolo[3,2-b]quinolin-2-ones (4a and 4c). The cyclization of 3-N-alkylethoxycarbonylacetamidoquinoline 1-oxides (3b and 3d) occurs upon heating with Ac2O at 60-degrees-C. 3-(3,3-Dicyanopropoxy) quinoline 1-oxide (5) also cyclizes to the pyranoquinoline (6) when treated with Ac2O at room temperature in chloroform-DMF.
Enantioselective transfer hydrogenation, a key step for the synthesis of 3-aminotetrahydroquinolines
作者:Alexandre Aillerie、Vincent Lemau de Talencé、Clément Dumont、Sylvain Pellegrini、Frédéric Capet、Till Bousquet、Lydie Pélinski
DOI:10.1039/c6nj02249a
日期:——
An enantioselective transfer hydrogenation has been successfully achieved to furnish 3-aminotetrahydroquinolines. The reaction was conducted in the presence of Hantzsch dihydropyridine and a catalytic amount of chiral phosphoric acid under mild conditions.
Redox-Neutral Cross-Coupling Amination with Weak <i>N-</i>Nucleophiles: Arylation of Anilines, Sulfonamides, Sulfoximines, Carbamates, and Imines via Nickelaelectrocatalysis
A nickel-catalyzed cross-coupling amination with weak nitrogen nucleophiles is described. Arylhalides as well as aryl tosylates can be efficiently coupled with a series of weak N-nucleophiles, including anilines, sulfonamides, sulfoximines, carbamates, and imines via concerted paired electrolysis. Notably, electron-deficient anilines and sulfonamides are also suitable substrates. Interestingly, when